Athletics has become an integral part of society, with multiple television channels dedicated to sporting events, with professional athletes promoting all sorts of products, and with the public holding star athletes—both amateur and professional—in high regard, so as to support financial rewards such as college scholarships, sponsorship opportunities, and other revenue-generating careers. With greater general attention on athletics comes greater attention on improving athletic performance. Today's athletes, beginning as early as the elementary school level, specialize in particular areas and train year-round to improve their skills and their conditioning. With athletics leading to a possibly lucrative career for some, and to academic assistance in the form of scholarships to others, more and more athletes have looked to improve their performance in various manners.
Good coaching and personal dedication are some of the best known ways to improve an athlete's performance. A talented coach can often observe subtle problems in an athlete's style of play, and can direct the player to correct those problems. Likewise, a talented trainer can direct an athlete to follow certain regimens to improve physiological weaknesses.
Despite the talent and experience obtained by many top coaches or athletic experts, human perception can capture and fully appreciate only a small subset of the factors that affect an athlete's performance. Thus, despite years of observing how different athletes compete in a given sport or having competed for many years themselves, the most highly skilled trainers and coaches still do not have the ability to quantify very small differences in motion of what they see. These differences in motion can be the most important elements in comparing and diagnosing a player's skill. Also, techniques that rely on human observation and judgment are prone to a high degree of opinion or bias based on the perceptions of any single observer. This bias, and the wide variability of what any given observer believes they are seeing, negatively affects the advice that coaches and trainers can provide to athletes, and also negatively affects the athletes' perception of the advice they are being given (i.e., an athlete may ignore good advice if they think that the provider of the advice does not appreciate their abilities).
In some sports that require a combination of physical athletic skill, muscle memory, and hand-eye coordination skills to be used while simultaneously moving an athletic object, such as a ball, while under pressure situations, the ability to objectively quantify and compare discrete skill differences between players is almost impossible using human perception. The net effect of the inability to standardize the unseen elements of skill has been an over-reliance on only the measurable physical aspects of certain sports, such as athletic speed, strength, and jumping, which causes many highly skilled athletes to be overlooked.